Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/01/21
AREA FORECAST DISCUSSION
National Weather Service Albany NY
1056 PM EDT Sun Oct 31 2021
.SYNOPSIS...
Cooler and drier air will be working its way into the region
for tonight. Clouds will be breaking for some sunshine on
Monday, with gusty westerly winds and cooler afternoon
temperatures. Aside from a brief shower on Tuesday, most of the
region will be dry and cool through the middle of the week,
although a few lake effect rain and snow showers could impact
the Adirondacks.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 10:30PM...Shortwave ridging is building behind our
departing upper level low that continues to exit through Quebec.
While stratocumulus clouds have diminished some as seen on the
latest GOES16 night fog channel, westerly winds ushering in
cooler air aloft over the warm Lake Ontario and Erie waters
will likely replenish enough low-level moisture to maintain at
least partial cloud coverage. However, pockets of clear skies
downwind of the eastern Catskills/southern Adirondacks and in
parts of the mid-Hudson Valley and NW CT are likely which will
result in radiational cooling and temperatures cooling down.
Speaking of which, temperatures have been a bit mild so far this
evening between the clouds and somewhat breezy winds. NYS
mesonet and ASOS sites have remained in the low to mid 50s with
the higher terrain still in the upper 40s. During any breaks or
clearing, temperatures will cool down but dew points still in
the mid 40s will impede temperatures from cooling down too much.
Still expected lows dropping into the mid to upper 40s.
Our secondary front will likely move through the region by 08
- 12 UTC with west-northwest winds turning gusty behind it
reaching up to 15 - 25kts and clouds downstream of the
Adirondacks and Catskills having a better chance of clearing
out. Westerly flow will likely act to maintain stratocumulus
down the Mohawk Valley into the Capital Region and Berkshire as
it funnels lake moisture down the east- west oriented valley. We
continued slight chance POPs to account for some brief/isolated
showers for areas mainly west of the Hudson River during the
frontal passage as supported by the HRRR but these showers will
quickly dry up as they head eastward.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
Our region will be situated within west to southwest flow aloft
ahead of an approaching upper level trough for Monday into
Monday night. Most of the area will continue to be dry with a
partly to mostly clear sky. The exception will be far
northwestern areas, as a few lake-effect showers will continue
for the western Adirondacks with a mostly cloudy sky. Best
chance will be early Monday, as the flow becomes more
southwesterly, these showers will start to shift north of the
area. It will continue to be breezy through the day on Monday,
with some westerly gusts over 25 mph at times. Temps will be
cooler than recent days, with highs in the mid 40s to mid 50s.
Lows on Monday night will be in the 30s across the entire area.
On Tuesday into Tuesday night, upper level trough will be
getting close to the area, helping to produce some precip.
Since overall moisture is limited, any showers will need to be
aided from the eastern Great Lakes. Some lake enhanced showers
will be developing off both Lake Ontario and Lake Erie during
the day Tuesday and into Tuesday night. Rain and snow showers
will move across the Adirondacks, with the best chance of seeing
snow across the higher terrain for Tuesday night. Any
accumulation would be limited to just a dusting across grassy
surfaces within the higher elevations.
In addition, moisture extending from Lake Erie will be allowing
for showers to spread across the Southern Tier of New York
towards the Catskills and into Schoharie County. Some of these
showers could even reach into parts of the Capital Region and
mid Hudson Valley. Most of these will be rain showers, although
some wet snow flakes are possible across the highest terrain of
the Catskills Tuesday night, but little to no accumulation is
expected.
Otherwise, it will be fairly cloudy and cool for Tuesday into
Tuesday night with a lingering westerly breeze. Daytime temps
will be in the 40s for Tuesday (some low 50s in the Hudson
Valley). Overnight lows for Tuesday night will be cold, with a
widespread freeze for most of the area, as temps should range
from the upper 20s to low 30s.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Slightly below normal temperatures will develop through the long
term period, with mainly dry conditions outside of some lake
effect/enhanced activity through early Thursday. Uncertainty then
increases for Friday-Sunday regarding possible southern stream
energy/moisture phasing with northern stream trough. Current trends
in 12Z/31 deterministic and ensemble guidance suggest phasing
potential has trended farther south and east compared to previous
cycles, however still enough spread among ensemble members to keep
some chances in for next weekend.
For Wednesday-Thursday, mainly lake effect/enhanced activity is
expected across the SW Adirondacks/western Mohawk Valley, with some
occasional extensions possibly reaching into the Hudson River Valley
from Albany north, as well as into southern VT. Outside of any lake
effect activity, mainly dry conditions are expected. Max temps
mainly 45-50 in valleys, and mid 30s to lower 40s across higher
terrain. Overnight lows mainly in the 20s to lower 30s, with some
possibility for teens across sheltered areas within the southern
Adirondacks/Greens.
For Friday-Sunday, main forcing would be associated with approach of
northern stream trough and any added southern stream
moisture/energy. For now, will keep mainly chance PoPs, greatest for
areas south of I-90. However, if current trends continue, these
chances may eventually decrease. As for P-type, mainly rain in
valleys, with perhaps rain/snow mix for higher elevations, although
if stronger dynamics eventually extend farther north, greater areas
of snow could occur, even in some valley areas.
As for temps Fri-Sun, high temperatures mainly mid 40s to lower 50s
in valleys, and mid 30s to lower 40s across higher elevations.
However, colder max temps would be possible should any steady
precipitation occur. Overnight lows in the lower/mid 30s, although
could be colder if clouds/precipitation remains limited with a storm
track farther south and east.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Low pressure will continue tracking northward through Quebec
overnight. A cold front will cross the TAF sites around
daybreak Monday.
For tonight, mainly VFR Cigs are expected. However, a few
periods of MVFR Cigs will be possible through 04Z/Mon at KALB
and especially KPSF. In addition, a few sprinkles will be
possible during this time as well.
A cold front will then track through the TAF sites between
roughly 11Z-13Z/Mon. Little if any precipitation is expected
with the front, with clouds (VFR Cigs) gradually decreasing
Monday afternoon from southwest to northeast.
Winds will be from the southwest to west at 5-10 KT overnight,
then increase and shift into the west to northwest with the
frontal passage Monday morning, with speeds increasing to 10-15
KT, and occasional gusts of 20-30 KT possible, especially at
KALB and KPSF during the late morning through mid afternoon
hours.
Should any winds locally decrease to less than 5 KT tonight,
there would be low level wind shear, as winds around 2000 FT AGL
increase from the west to 30-35 KT. For now, have only included
mention at KPOU where best chance for lighter surface winds will
be. However, trends will need to be watched at KGFL and KALB in
case similar conditions develop.
Outlook...
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Moderate Operational Impact. Chance of SHRA.
Tuesday Night: Low Operational Impact. Slight Chance of SHRA.
Wednesday: Low Operational Impact. Isolated SHRA...SHSN.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: Low Operational Impact. Slight Chance of RA.
&&
.FIRE WEATHER...
As a storm continues to depart, showers will be ending this
evening with cooler and drier air starting to work into the
region. RH values will fall as low as 45 to 55 percent for much
of the region on Monday afternoon. Westerly winds will be 10 to
15 mph for tonight into Monday, with some gusts over 25 mph
possible. Most of the upcoming week will be dry.
&&
.HYDROLOGY...
Rainfall from Friday night through this morning allowed for some
notable rises on rivers and streams, mainly across western New
England and within the Lake George area. However, any additional
rainfall through this evening into tonight looks light,
generally under a quarter of an inch. As a result, rivers and
streams will be cresting and starting to fall.
Through much of the upcoming week, dry weather is expected for
most of the time. There could be a few lake-effect rain or snow
showers across the Adirondacks, but little precipitation is
expected in total. As a result, rivers and streams will
continue to recede and level off through the week. The next
chance for widespread precipitation may not be until late in the
week.
For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our
website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...Frugis
NEAR TERM...Speciale
SHORT TERM...Frugis
LONG TERM...KL
AVIATION...KL
FIRE WEATHER...Frugis
HYDROLOGY...Frugis
Area Forecast Discussion
National Weather Service Boston/Norton MA
1024 PM EDT Sun Oct 31 2021
.SYNOPSIS...
Mainly dry and cooler for much of the upcoming workweek, with
temperatures trending slightly below normal for early November.
Other than a period of lake-enhanced precipitation across the
interior Tuesday night, much of the workweek is dry with cooler
than average temperatures. Monitoring a potential coastal storm
around later Friday into the weekend, but this is not set in
stone and uncertainty in details on this system remains large.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
No major changes to the forecast this evening. Mid and upper
level clouds continued to move off to the NE as a mid level
trough finally departs from our region. Lower clouds fed by flow
over the Great Lakes remained banked up against the Berkshires.
Still expecting a cold front to arrive late tonight. Overall
forecast was in good shape, but did make some tweaks to reflect
observed trends.
700 PM Update:
Utilized latest HRRR and the time-lagged HRRR ensemble to
adjust PoP through next couple hours for isolated to scattered
shallow- instability driven showers.
Seems the RAP has the best handle on this per soundings, with
shallow instability shown in those profiles diminishing through
8 PM, correlating with decrease in areal coverage of these
showers. Mid-upper level trough axis through SNE expected to
shift offshore by midnight. Mostly cloudy to overcast mid level
clouds initially should trend toward mostly clear to partly
cloudy as the trough axis shifts offshore and we get into weak
subsidence. Have also upped hourly temps thru midnight on
basis of thicker mid-level clouds and westerly breezes keeping
PBL more mixed and milder; more clearing and modest CAA
overnight should bring temps to expected lows in upper 40s to
low 50s.
Previous discussion:
Based on the circulation evident in visible satellite and
surface observations, the low center has moved in to far
northern Maine/southern Canada. The widespread rain is well to
our north, but the low/cold pool remains overhead leaving some
instability clouds and isolated showers, mainly over the
interior. These will continue this afternoon and early evening,
but the vast majority of location will remain dry. Temperatures
have warmed up quite a bit, into the upper 60s (as warm as 66-67
in some spots). Enjoy this anomalous warmth while it lasts
because change is on the horizon! Winds will begin to turn from
the WSW to the W tonight ahead of an approaching dry cold front.
Sandwiched between an exiting low and incoming high, winds will
be breezy enough to keep the boundary layer from decoupling.
Drier air, though, means cooler lows, in the upper 40s.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
A cold front crosses southern New England as the low lifts further
into Canada, though a dry atmospheric column will keep rain or even
many clouds from accompanying it. Mainly it will be the start of
a wake up call that it is indeed early November. 850 mb temps of
near -3C aloft will allow for highs in the upper 50s and low
60s. Along with the cooler air comes gusty winds (20 to 30 mph)
during the day, diminishing in the evening as the pressure
gradient relaxes. Quiet overnight as high pressure builds in.
Could be a good night for radiational cooling but some mid and
high level clouds move in overnight which may limit it. Even so,
lows will be around 10 degrees colder than the night previous,
in the upper 30s inland, 40s along the coast.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Highlights:
* Possible lake-enhanced rain/higher elevation snow showers
across northwest MA Tue night, otherwise mostly dry Tue thru
Thurs. Temps cooler than average for early Nov.
* Temps trend cooler each day to near to slightly below normal
levels for early Nov.
* Still monitoring a possible coastal storm Fri night into the
weekend. While most models are currently dry, can`t yet
discount a potential coastal low. Uncertainty still is high.
Will have high astro tides Fri into Sun.
Overview:
Strong confidence in longwave trough becoming established into
the Northeast states in this period. Omega block pattern across
the northern part of North America with amplified ridging across
western Canada upstream of the described trough. Multiple
shortwave disturbances aloft will dig southward around the 500
mb geopotential height gradient and round the base of the
longwave trough into New England through at least Wednesday,
leading to a couple of potential periods of cloudiness, light
rain and/or higher elevation snow showers as temperature
profiles aloft cool.
There still remains large uncertainty in the forecast looking
into late week into the weekend (and, even into early next
week). The prior/00z guidance showed varied handling of
shortwave trough energy digging into the Southern Plains or
lower Ohio Valley late in the week, which resulted in vastly
different mass-field depictions. However, notably the
international deterministic guidance with today`s 12z guidance
has backed off on earlier depictions of a coastal low around
Friday or the weekend, offering dryness with a more full-
latitude positive trough in the 12z GEM/ECWMF solutions. Worth
noting that GEPS/EPS means still lend support to a coastal low
bringing precip in for the weekend, so not yet something we can
waive off as yet. PoP was decreased by about 10 percent compared
to NBM to slight/low Chance in deference to the ensembles. Will
have to see if this offshore solution holds, a solution that
the GFS has steadfastly reflected in the last several cycles.
Temperatures to trend slightly cooler than normal for early
November through the workweek, then moderate closer to
seasonable/within a couple degrees of climo.
Details:
Tuesday through Thursday:
Most of Tuesday looks dry, though a limited-moisture shortwave
trough ripples around the longwave trough into New England
Tuesday night. This leads to increasing clouds second half of
Tues into Tues night, with lake-effect moisture leading to the
potential for some higher-elevation snowflakes across the
Berkshires and northern Worcester Hills. It may also induce some
showers across southeast New England and the adjacent coastal
waters. Temps still look too warm for any snow to stick, and any
rain showers should be on the light side. Highs in the 50s,
with low-mid 30s lows in the interior/upper 30s for the urban
areas, coastal eastern MA and upper 40s Cape/Islands.
Next shortwave trough moves across northern New England on
Wednesday. This feature may just lead to a period of partial
cloudiness across northwest MA with any lake effect
moisture/precip tending to be confined to areas across interior
northern New England. Mainly mostly clear and dry eastern MA/RI
but with somewhat more clouds north and west. Trending clear by
evening and should be one of the coldest nights we`ve seen thus
far in autumn with good radiational cooling likely. Lows in the
mid/upper 20s to lower 30s across interior MA/CT, low 30s into
the coastal plain in MA, and mid 30/upper 30s for southeast and
eastern MA and RI.
Still under cyclonic flow aloft for Thursday, though broad
surface ridge of high pressure extends eastward into Southern
New England with weak 500 mb height rises ahead of upstream
troughing over the Ohio Valley. Should lead to dry weather with
partly cloudy skies and highs mid 40s to lower to mid 50s; lows
upper 20s-mid 30s interior locales and mid/upper 30s eastern
MA/RI, the urban areas and Cape Cod/Islands.
Friday into Next Weekend:
As mentioned, uncertainty remains for Friday into the weekend
regarding a potential coastal low pressure that could affect our
area in this period. GFS and to an extent its ensemble have
been the most steadfast in offering mainly dry weather for this
period. The 12z international deterministic guidance has backed
off its more bullish coastal low solution depicted in earlier
runs to now maintaining surface ridging with coastal low well
south of 40N/70W, though their ensemble means still point at the
potential. Out of deference to the ensembles, ended up reducing
PoP to low end chance levels. Certainly higher than what the
deterministic models show but avoids a potential windshield-
wiper effect with the forecast. PoP can then be adjusted up or
down pending subsequent guidance trends. Kept temps close to NBM
values here.
One thing we do have to watch is potential for coastal flooding
next weekend. Astro tides are at their monthly highs with
Boston Harbor at 12.1 ft MLLW on Saturday, with flood stage at
12.5 ft. The extent of this risk is currently still in some
question. Absent a significant coastal low or stronger
onshore/NE winds, splashover still seems possible or at worst
minor coastal flooding. But that coastal flood threat could be
larger depending on a more closer-to-SNE track regarding
potential coastal storminess.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Tonight: High confidence.
SCT-bkn VFR ceilings. West winds around 6-12 kt, with gusts
20-25 kt across the terrain in the Berkshires.
Monday...VFR. Gusty west winds developing behind a cold front,
becoming light Monday night.
KBOS Terminal...Moderate confidence in TAF.
KBDL Terminal...Moderate confidence in TAF.
Outlook /Tuesday through Friday/...
Tuesday: VFR.
Tuesday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.
Wednesday through Thursday Night: VFR.
Friday: Mainly VFR, with local MVFR possible. Slight chance
SHRA.
&&
.MARINE...
Forecaster Confidence Levels.
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Winds will continue to diminish this evening. Small Craft
Advisories continue for lingering seas into Monday. Gusty winds
redevelop Monday as a cold front crosses the waters, but
diminish again Monday night.
Outlook /Tuesday through Friday/...
Tuesday: Winds less than 25 kt. Slight chance of rain showers.
Tuesday Night: Winds less than 25 kt. Chance of rain showers.
Wednesday: Winds less than 25 kt. Seas locally approaching
5 ft.
Wednesday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft.
Thursday through Thursday Night: Winds less than 25 kt. Seas
locally approaching 5 ft.
Friday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 AM EDT Monday for ANZ231-232-235-
237.
Small Craft Advisory until 8 PM EDT Monday for ANZ250-254>256.
Small Craft Advisory until 4 PM EDT Monday for ANZ251.
&&
$$
SYNOPSIS...Loconto/BW
NEAR TERM...Belk/Loconto/BW
SHORT TERM...BW
LONG TERM...Loconto
AVIATION...Belk/Loconto/BW
MARINE...Belk/Loconto/BW
Area Forecast Discussion
National Weather Service State College PA
1122 PM EDT Sun Oct 31 2021
.SYNOPSIS...
An upper trough, centered over the Great Lakes, will slowly
pivot eastward into Pennsylvania by late next week. A weak
shortwave rounding the base of the trough will swing through the
area on Tuesday. A developing coastal low is then expected to
form late in the week, but it is uncertain whether it will pass
close enough to affect central Pa.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A cold front entering northwest Pa at 03Z will sweep through
central Pa later tonight, accompanied by a round of showers over
primarily the northwest mountains. This area will be closest to
the track of the mid level shortwave passing over the eastern
Grt Lks. The 12Z HREF and 18Z NAMNest and HRRR both support
categorical POPs across parts of Warren and Mckean counties late
this evening, with rapidly diminishing POPs further south and
east.
A few lingering lake effect rain showers are possible across the
northwest mountains late tonight. However, falling inversion
heights below 800mb suggest any showers should end by dawn.
Latest guidance support min temps ranging from the upper 30s
across the Alleghenies, to the mid 40s over most of the Susq
Valley, some 5-10F above normal for this time of year.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
A chilly west-northwest flow and still warm lake water should
result in lingering lake effect stratocu across the northwest
mountains Monday, while downsloping flow yields mostly sunny
skies across the southeast half of the forecast area. Hires
models indicate a few lake effect rain showers could persist
across portions of Warren and Mckean counties, but low
inversion heights indicate any showers will be very light.
Mixing down 850mb temps of 0 to -2C translate to max temps
ranging from the mid and upper 40s over the highest terrain of
the Alleghenies, to the mid and upper 50s over the Lower Susq
Valley.
Clouds increase Monday night ahead of shortwave trough diving
through the Great Lakes. The combination of height falls and jet
induced lift should result in an area of light rain expanding
from the Ohio Valley eastward into southwest Pa late Monday
night. Model soundings become just cold enough to potentially
result in the first snowflakes of the season over the higher
elevations of the Laurels around dawn Tuesday.
Further north, lake effect activity will ramp up late Monday
night with approach of shortwave. Model soundings indicate temps
are likely to become cold enough for rain showers to change to
snow showers after midnight across the higher terrain of northwest
Pa. As will likely be the case over the Laurel Highlands,
surface temps above freezing and light qpf will make snow accums
unlikely.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Upper level trough to our west will bring additional disturbances
through. Once disturbance will move across Tuesday bring a
chance for showers. Any showers Tuesday morning in the northwest
may mix with a little snow before temperature warm enough
during the day. Tuesday night lake enhanced and upslope showers
are possible over the northwest and again colder locations will
mix with and change to snow especially over higher terrain. Lake
enhanced clouds and chance for showers will remain over the
northern tier Wednesday with any showers changing back to rain
as temperatures warm. For the Susq Valley, morning frost
Wednesday followed by some sunshine and highs once again making
it to about 50.
Thursday morning still looks to be the coldest so far, as
surface high builds over the area. Many places across the
western and northern mountains should see lows in the mid 20s
with temps of 30-35 in the Lower Susq Valley.
All medium range guidance indicates a deepening upstream trough
will spawn a coastal low late next week. The latest operational
guidance suggests the coastal low will remain too far east to
affect central Pa. However, a sizable minority of EC ensemble
members are slower and deeper with approaching trough and
further north/west with surface low, resulting in measurable
precipitation across central Pa Friday into Saturday. Thus, will
maintain a less than 40pct chance of precipitation Friday/Saturday,
with the highest POPs across the south. If precipitation
reaches central Pa, the air mass looks cold enough to support a
rain/snow mix, with the central mountains most likely to see
snow. So the bottom line is that odds favor fair weather late in
the week, but there remains a low chance of a plowable snow
over the higher terrain of south-central Pa.
Latest ECENS and GEFS plumes favor fair and seasonable
conditions by late next weekend, as coastal low lifts out and
surface ridge builds in from the west.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
TAF package in good shape. Main change was BFD, few showers
moving across BFD.
Earlier discussion below.
00Z TAFS sent.
Mainly VFR conditions now. While there could be a lower
CIG at times tonight and early Monday, widespread low clouds
and showers are finally out of the area.
Winds will pick up a bit again on Monday, but still not bad
for the 1st of Nov.
The overall pattern this week supports colder weather, but
not really the right setup for widespread clouds and showers
off the Great Lakes.
There is a chance of some showers again after Monday, but
nothing real heavy or widespread.
Outlook...
Tue...PM showers psbl.
Wed...MVFR cigs/showers psbl northwest airspace.
Thu...PM rain psbl southern airspace (low confidence).
Fri...Rain/snow psbl but very low confidence.
&&
.CLIMATE...
October 2021 will be remembered for its persistent warmth &
lack of cold nights. As we approach the end of the month, let`s
contextualize the record-setting warmth:
RECORD WARMEST LOWEST OCTOBER TEMPERATURES
(The temperature never fell below this value in October)
CURRENT RECORD OCT 2021 SO FAR
Harrisburg: 43F (1984) 43F (10/24)
Williamsport: 38F (1971) 39F (10/19,28)
State College: 38F (2014) 39F (10/24)
RECORD HIGHEST AVERAGE TEMPERATURE
(Average of all the highs and lows in the month of October)
CURRENT RECORD OCT 2021 (THRU 10/30)
Harrisburg: 62.0F (2007) 62.7F (RANKS 1ST MONTH-TO-DATE)
Williamsport: 59.4F (2007) 59.6F (RANKS 1ST MONTH-TO-DATE)
State College: 59.2F (2007) 59.4F (RANKS 1ST MONTH-TO-DATE)
Note that October 2007 ended with 4 nights with temperatures in
the 30s. Thanks to ample cloud cover, lows this weekend will be
in the upper 40s to low 50s, thus almost guaranteeing a record-
setting October.
RECORD HIGHEST AVERAGE LOW TEMPERATURE
(Average of all the low temperatures in the month of October)
CURRENT RECORD OCT 2021 TO DATE (DIFF FROM RECORD)
Harrisburg: 53.6F (1984) 54.5F (+0.9F)
Williamsport: 50.1F (2007) 51.3F (+1.2F)
State College: 49.8F (2007) 51.1F (+1.3F)
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Fitzgerald
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald/Steinbugl
LONG TERM...Watson/Fitzgerald
AVIATION...Martin
CLIMATE...Banghoff/Steinbugl
Area Forecast Discussion
National Weather Service Des Moines IA
1053 PM CDT Sun Oct 31 2021
...Updated for the 06z Aviation Discussion...
.DISCUSSION.../Tonight through Sunday/
Issued at 245 PM CDT Sun Oct 31 2021
The primary messaging highlights through the period include...
* Low end chances for light rain south Monday, otherwise little
in the way of precipitation through the period
* Frost/freeze conditions likely south Mon Night where headlines
are still possible
* Cool, below normal temperatures through the work week
Fair weather is expected tonight, with patchy frost possible
south dependent on cloud trends, but periods of mid clouds
continue ahead of a system moving through the central and southern
Rockies. Although the 1-3km thermodynamic support will weaken and
push south, stronger mid level kinematic forcing is expected to
advance through the lower MO Valley overnight into Monday bringing
with it chances for light rain south during the daylight hours.
The latest RAP and HRRR runs even suggest isolated weak convection
is possible in the evening hours along a secondary boundary,
aided by additional synoptic forcing as another PV anomaly drops
into the mean trough.
Subsidence and clearing skies should then set in late Monday
evening leading to widespread lows in the 20s, at or near the
coolest of the season for many locations. Confidence is higher
tomorrow night versus tonight that headlines will be needed
south, likely Freeze Warnings, where climatology and recent temps
have yet to end headlines for the season. The MO Valley surface
responsible for these cooler temps will linger for a few days
keeping temps below normal and highs no better than the 40s.
Looking from the middle portions of next week through the
weekend, the overall forecast still looks either dry or with only
a few token windows of precipitation. Confidence isn`t the best
with the GFS more progressive than CMC and ECMWF solutions which
emphasize a lingering trough through the OH Valley. Without any
clear suggestion which route to prefer at this point, and
considerable run to run changes since this morning, will continue
with the broad dry NBM consensus with all solutions either dry or
only depicting a brief light precip window either Wed or Thu. For
further ahead to end the week and into next weekend, there is good
agreement with a strong jet into the Pacific NW but considerable
disagreement on how the resultant upper trough breaks down with
the GFS and ECMWF 180 degrees out of phase, and the CMC still
fairly zonal. Thus there is some low end precip potential over the
weekend, but much like the thinking earlier in the week the
forecast will remain dry until confidence in a particular solution
increases. Regardless of solution, it appears temps should be at
or just below normal to end the period.
&&
.AVIATION.../For the 06Z TAFS through 06Z Monday night/
Issued at 1053 PM CDT Sun Oct 31 2021
Little change to previous package. Mid level clouds increasing
south sites with afternoon fair weather clouds expected north
sites aft 19z. Though VFR conditions will prevail, mixing will
increase over the area aft 19z with most sites gusting to near
20kts. Winds will decouple aft 23z most areas. /rev
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Small
AVIATION...REV
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
936 PM CDT Sun Oct 31 2021
.UPDATE...
Issued at 932 PM CDT Sun Oct 31 2021
Overall mainly minor adjustments were made to forecast elements
tonight. Sped up timing of precip a bit, radar showing the first
of a couple bands to affect the area tonight sliding roughly along
the Custer/Dawson/Buffalo/Sherman county line. After adjustments
and collab with neighbor WFO North Platte, decided to add Sherman
and Kearney counties to the Winter Weather Advisory. Also started
Dawson/Buffalo/Sherman immediately, other counties start at 11
PM.
&&
.DISCUSSION...(This evening through Sunday)
Issued at 319 PM CDT Sun Oct 31 2021
Cloudy skies have persisted across the local area today with light
returns on radar picking up a few sprinkles (and even report of a
few flurries in Dawson county) for much of the day. Expect clouds
continue to thicken and lower overnight as a frontogenetic band
of precipitation forms across the local area. All indications are
this band will set up very near I-80...with accumulating snowfall
possible across much of the local area by daybreak Monday. Still
some uncertainty in exact amounts and location of the band...with
the 18Z HRRR now indicating a strip of 0.5 inch liquid along and
just north of the I-80 corridor...but all models agree that the
heaviest precipitation should be mainly west of Highway 183...with
lesser amounts further east. Given the focus of the heavier
precipitation across our western counties and the fact that this
is the first snowfall of the season...went ahead and issued a
winter weather advisory for our westernmost 6 Nebraska counties
through the mid afternoon hours. That said...if additional models
continue to show increased precipitation like the HRRR...this
advisory may need to be expanded a bit further east to capture the
most significant impacts from this first wintry storm.
While temperatures aloft are plenty cold to support accumulating
snowfall...ground temperatures remain warm...and the main
accumulations should only be expected on grassy and elevated
surfaces...with slick conditions expected on area roadways as
snowfall is expected to rapidly melt on the warmer surfaces. The
only other concern in the short term was freezing temperatures and
the potential for a freeze overnight tonight. Given the winter
headline and marginal freezing temperatures (mostly in the 30-32
degree range), opted not to issue a freeze warning as the much
more impactful freeze is expected early Tuesday morning with
clearing skies across our north expected to allow temperatures to
plummet into the teens near Ord...to the mid to upper 20s across
much of the remaining forecast area.
Thereafter...there continues to be small chances for precipitation
across parts of the local area through Wednesday afternoon as
several weak perturbations wrap around the southern periphery of
the upper level trough. Overall...do not think this precipitation
will amount to much...with the best chances for any accumulating
precipitation beyond Monday afternoon existing primarily south and
west of the tri-cities.
Overall...several days of well below normal temperatures are
forecast...with morning lows expected to be near or below
freezing to start the day through next weekend...and afternoon
temperatures in the 40s mid-week...returning closer to climatology
(mid-50s) by the end of next weekend as high pressure aloft
returns to the local area. One exception will be the Friday
afternoon through Saturday time period when the latest models are
attempting to bring another system across the local area...but at
this time...the current forecast remains dry due to the poor
agreement and limited moisture.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 619 PM CDT Sun Oct 31 2021
Main forecast concern for this TAF period continues to lie with
increasing snow chances. Radar showing a bit of light snow
creeping into western portions of the coverage area, but models
still showing the better-more widespread activity occurring later
this evening/overnight. At least light activity looks to linger
through much of/if not all of this TAF period. Lowering ceilings
are also expected with time this evening/tonight, with visibility
restrictions possible with heavier snow. Overall winds through the
period are expected to remain light/variable.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...Winter Weather Advisory until 3 PM CDT Monday for NEZ072>074-082-
083.
Winter Weather Advisory until 3 PM CDT Monday for NEZ046-060-061.
KS...NONE.
&&
$$
UPDATE...ADP
DISCUSSION...Rossi
AVIATION...ADP
Area Forecast Discussion
National Weather Service Green Bay WI
623 PM CDT Sun Oct 31 2021
Updated aviation portion for 00Z TAF issuance
.SHORT TERM...Tonight and Monday
Issued at 255 PM CDT Sun Oct 31 2021
The latest RAP analysis and satellite/radar imagery show a digging
trough pushing into the western Great Lakes, and pushing a cold
front across Lower Michigan early this afternoon. Gusty northwest
winds continue behind the front, with gusts of 30 to 35 mph across
northeast Wisconsin. Scattered to broken cloud cover briefly
cleared over central WI, but additional cloud cover over
northwest WI has pushed into that area. As a colder airmass
settles into the region, focus of this forecast is cloud trends
and gusty winds.
Tonight...High pressure will be building from the northern Plains
to the central Mississippi Valley. The pressure gradient will
remain rather tight over northeast Wisconsin and back some to the
west. The backing of winds will keep lake effect rain and snow
showers along and north of the U.P. border and clouds over north-
central WI.
Low level winds of 20 to 25 kts will likely keep the boundary
layer churned up enough to prevent decoupling and stayed warmer
than the NationalBlend as a result. Temps will likely fall into
the middle 30s over Door county regardless, but enough wind should
prevent much in the way of frost.
Monday...Minor height falls will take place in the mid-levels
which might support clouds surging south with help from steepening
low level lapse rates. Downsloping will likely limit cloud cover
over northeast WI however. Winds will not be as breezy as today
with gusts in the 20 to 25 mph range, which will still make it
feel blustery. Cooler highs ranging from the upper 30s to middle
40s.
.LONG TERM...Monday Night Through Sunday
Issued at 255 PM CDT Sun Oct 31 2021
A fairly quiet week lies ahead. The only weather concern is some
light lake effect snow across the far north early in the work
week, before a fairly large ridge builds into the area on the tail
of the cold air currently moving into the Great Lakes area.
Monday night through Wednesday morning...Fairly strong cold air
advection in the lower levels from the northwest flow pattern
will be ongoing at the beginning of the extended. With a fairly
strong inversion aloft and delta Ts off Lake Superior in the upper
teens, expect that lake effect snow will be ongoing at times for
far northern Wisconsin. Soundings do show the chance to mix to
rain briefly in the daytime hours, but expect mostly flurries or
light snow. There are a few indicators for some weak PVA both
Monday night and Tuesday night, which could bring a little
enhancement to any snow showers. Overall however, any
accumulations will be fairly light and mostly limited to the far
north. Expect any lake effect activity to come to an end Wednesday
morning, as the surface high follows on the tail of the cold and
lower level winds shift to the west.
Rest of the extended... This will be a fairly quiet portion of the
forecast, with the upper trough off to our east and the upper
ridge moving into place for the late part of the week and next
weekend. Expect mostly quiet conditions for this portion of the
forecast. The only change will be a gradual moderation of
temperatures, as weak WAA returns for the late part of the week.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 622 PM CDT Sun Oct 31 2021
VFR weather is expected through at least Monday night. The possible
exception is a chance of lake effect clouds producing MVFR ceilings
and snow showers north of a RHI to IMT line Monday afternoon and
evening.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......Uhlmann
AVIATION.......RDM
Area Forecast Discussion
National Weather Service North Platte NE
856 PM CDT Sun Oct 31 2021
.UPDATE...
Issued at 855 PM CDT Sun Oct 31 2021
Current radar imagery has a 20 to 30 mile wide band of
precipitation centered along along a line from Lewellen Nebraska
to North Platte. Within this band, moderate snow continues to fall
and so far, we have received around an inch of snow at the North
Platte Airport on grassy surfaces. Looking at the latest HRRR, the
main band of precipitation has trended slightly farther north
compared to the ongoing forecast. After collaborating with GID,
decided to add Logan and Custer county to the winter weather
advisory. For Custer county, the advisory is mainly for the
southern half of the county, as some locations across far northern
portions of the county, may see little to no snowfall.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 351 PM CDT Sun Oct 31 2021
The models have really perked up on the forcing for snow tonight and
Monday morning. We are now getting a good signal for periods of
strong lift in the DGZ, which for this system is far aloft at
600mb-500mb.
WPC noted that CSI banded snow would likely develop in the DGZ and
suggested a good chance for 1 inch per hour snowfall rates
tonight. This is supported by the HREF, SREF and NAM models which
suggest visibility will fall to 1/2 mile during periods of heavy
snow tonight. The RAP and HRRR models show 1 hr QPF totals around
0.10 inches which would be 1 inch per hour snowfall rates.
A coupled 300mb jet is partly responsible for the stronger forcing
shown by the models. The coupled feature develops across the
Panhandle this evening and translates east into cntl Nebraska
overnight.
The snow forecast leans on the NBM which is in the middle of the
model forecast envelop for highest QPF totals of around 0.50 inches.
Some models like the NAM12 and GEM regional suggest a more southward
track of what appears to be a 50 or so mile wide area of 5-inch
snowfall totals while other models like the SREF, GFS and HRRR are
farther north.
Thus, some models favor areas along and south of Interstate 80 for
the best snowfall while the nrn models favor areas along and north
of the Interstate into the srn Sandhills. Since satellite and radar
this afternoon show enhanced returns north of the Interstate, the
forecast favors areas along and north of the Interstate for the best
snowfall. Arthur and McPherson counties have been added to the
Winter Weather Advisory in effect tonight and Monday morning.
Snow levels across the Panhandle Saturday night were operating
around 4000ft. These levels should fall to 3000ft late this
afternoon and then lower overnight. A push of dry sfc air moving
through the Sandhills should provide evaporative cooling for a rapid
changeover from rain to snow. Temperatures aloft at 850mb and above
are below 0C and no warm air advection is predicted by the models.
.LONG TERM...(Tuesday through Sunday)
Issued at 351 PM CDT Sun Oct 31 2021
Two more upper level disturbances will move across the Rockies
and get caught up in a deepening upper low across the ern Canada.
Both of these disturbances will pass through Colorado and Kansas,
south of Nebraska. Chance-slight chance POPs are in place across
southwest Nebraska for these systems and QPF totals of a few
hundredths of an inch are predicted across swrn Nebraska.
The SREF is signaling persistent stratus through Wednesday night.
This is the result of trapped moisture beneath a broad area of
sfc high pressure stretching from Nebraska to the northeast U.S..
The prospect of a radiation night with temperatures falling into
the teens appears low for this reason; 20s for lows are in place
instead.
Temperatures should rise Thursday and Fridays as h850mb temperatures
will rise to 10C. 10C would support highs in the 60s but the
blended forecast ignores this and continues to advertise highs in
the 50s. Look for later forecasts to mark highs up into the 60s
as suggested by the ECM and GFS guidance.
The ECM and GFS are at odds Saturday and Sunday. The problem is a
long wave trof moving ashore across the Pacific Northwest. The
GFS will amplify the system across the Dakotas while the ECM
shears the system out across srn Canada. If the GFS verifies then
a strong cold front would sweep into Nebraska vs the ECM
continuing mild weather. By Sunday, the models are 15C apart with
temperatures at h850 which equates to about a 20 degree fahrenheit
difference forecast highs. The weekend forecast will have to wait
for the models to converge for a reliable forecast.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 655 PM CDT Sun Oct 31 2021
For southwest Nebraska including KLBF, MVFR conditions this
evening will turn to IFR and LIFR conditions later in the night
and tomorrow morning as snow falls in the area. The snow will
begin to decrease later in the morning and through the afternoon,
but low ceilings will still keep conditions IFR. In northern
Nebraska including KVTN, conditions should remain VFR through the
night, but will turn to MVFR tomorrow morning as ceilings drop and
light snow falls for several hours. Conditions should turn back
to VFR by the afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 1 PM CDT /noon MDT/ Monday for
NEZ022-035>038-056>059-070-071.
&&
$$
UPDATE...Buttler
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Meltzer
Area Forecast Discussion
National Weather Service Marquette MI
919 PM EDT Sun Oct 31 2021
.UPDATE...
Issued at 919 PM EDT SUN OCT 31 2021
...Lake-effect continues this evening with potential for minor snow
accumulations...
Despite sfc obs remaining above freezing, model soundings suggest
wetbulb zero heights to remain only a couple hundred ft off the
ground, with a lowering trend through the evening to overnight
hours. An impressive band of lake-effect(radar suggesting upwards of
15kft convective depth) is impacting Ontonagon County this evening
and looks to continue for the next few hours, slowing shifting
northward as winds back slightly. In an area void of webcams, it is
tough to say if there is much accumulation at this time, but up the
road on M26, there looks to be a dusting of accumulation near Twin
Lakes and Nisula. Made some minor adjustments to the going forecast
to ensure that snowfall was in the forecast due to the low wbz
heights. Here at the office, we have had off and on showers through
the evening, with a mix of rain and snow, the latest band of showers
was all snow. With 2 inch soil temps in the mid to upper 40s, will
take a steadier band of precip to allow accums, but a sloppy inch or
two could be obtained overnight where bands remain over head for
some time.
&&
.SHORT TERM...(This evening through Monday)
Issued at 258 PM EDT SUN OCT 31 2021
Water vapor imagery and RAP analysis show a closed low over northern
Ontario with a shortwave trough moving across the Upper Great Lakes
this afternoon. At the sfc, NW winds are gusty behind the cold front
which exited the area this morning with the strongest gusts of 30-35
mph across the Keweenaw and shoreline areas east of Marquette. Main
lake effect shower activity by this afternoon has been confined to
mostly to the east half and even that has been weakening in
intensity due to fairly dry air upstream as depicted by the
soundings.
Tonight, expect an uptick in wnw flow lake effect showers as 850 mb
temps lower into -5C to -7C range and moisture depth increases
upwards of 15kft. With lake induced equilibrium levels rising to 15-
20kft and with increased moisture depth compared to today, shower
intensity will likely be briefly heavy at times tonight. Wet bulb
zero heights falling well blo 1500ft across the area will support
pcpn mixing with snow at times even close to Lake Superior. Given
the potential depth of convective mixing, pcpn may end up being more
graupel type at times, rather than snow, in heavier showers near the
lake. Under wnw flow, low-level convergence will likely be maximized
from central Ontonagon County into southern Houghton and Baraga
County over the w and east of Munising over the eastern fcst area.
So, expect greatest pcpn coverage in those areas. Over the w, 1-2
inches of snow accumulation is possible over the high terrain,
particularly in Baraga County. Even over the e, some sloppy snow
accumulations up to an inch may be possible inland from the lake.
Expect low temps generally in the upper 20s/lower 30s, except mid
30s/upper 30s F near Lake Superior.
Monday, expect more of the same as 850 mb temps maybe fall slightly
to -6 to -8C late in the day. Best low-level convergence areas look
to be in the same areas so again expect best lake effect shower
coverage generally east of Munising and over the higher terrain of
Ontonagon, southern Houghton and Baraga counties, perhaps reaching
into nw Marquette County. Cooler daytime times over the west will
favor the higher terrain of Baraga County for maybe another 1-2
inches of slushy snow. Expect highs ranging from generally the upper
30s west to the lower to mid 40s central and east.
.LONG TERM...(Monday night through Sunday)
Issued at 314 PM EDT SUN OCT 31 2021
Lake effect precipitation will be the main challenge in the long
term with long wave troughing over eastern Canada into the Great
Lakes though mid-week and a few different shortwaves dropping south
through the area bringing reinforcing colder air, increased moisture
and instability.
Though mid-week the low levels are relatively dry at times with
inverted-v type soundings. However, the more recent guidance is
showing a bit more moisture in the low levels. This should result in
moderate and possibly brief heavy showers at times as the atmosphere
becomes more favorable with the passing shortwaves. Precipitation
types will be mainly a rain/snow mix near the shorelines with all
snow inland during the overnight hours, transitioning to a mix
during the daytime. Blended QPF guidance is around a quarter to half
inch in the west Monday night into Tuesday morning with up to three
quarters of an inch over the east, mainly east of Munising. Snow
amount may be sufficient for advisories for inland locations in the
west and northwest lake effect belts, mainly during the overnight
hours when temperatures will be more favorable for all snow and
accumulations. The current forecast is for 2 to 4 inches in the east
(inland) and 3 to 5 inches in the high terrain of the central/west.
These amounts are in-line with the NBM 50th percentile 24 hour snow
amounts. Some of the models are showing a more extreme precipitation
event with NBM 90th snow amounts approaching 6 to 8 inches in the
higher elevations of the central and west along with inland
locations in the east. I wouldn`t be surprised to see a few higher
end snowfall reports where banding is more persistent. Tuesday night
into Wednesday looks like the best coverage of lake effect
precipitation will be in the east.
As far as support for the lake effect precipitation, the first
shortwave arrives Monday night and Tuesday, dropping south out of
Ontario and tracking over the U.P. This brings steepening mid-level
lapse rates with lake induced convection equilibrium levels reaching
to 20 kft, with 850mb temps around -6C. Convergence increases over
the east supporting a WNW to ESE orientated band for the east while
some convergence over the west in Ontonagon and Houghton counties
should help organize some of the bands there. Instability is
strongest in the east with the better fetch, sfc based cape of 200
to 400 J/kg are forecast by the NAM/GFS with lake induced cape
approaching 800 J/kg in the model bufrs. As the shortwave passes
another will be on its heals.
The second shortwave arrives Tuesday night and looks like it may
track south of the U.P., helping to bring the mean low level winds
more northerly with increased convergence over the eastern half of
the lake favoring the N to NW lake effect wind belts. The GFS brings
strong convergence close to the Marquette County shoreline on
Tuesday night so we could at least see the lake effect bands shift
west into western Alger and far northeastern Marquette County. 850mb
temps fall to around -10C however the mid-levels will be slightly
warmer during this time period which will lower lake induced
equilibrium levels to around 10 kft. The boundary layer will be a
bit colder which could bring accumulating snowfall closer to the
Lake Superior shoreline.
Things dry out for Thursday though the end of the week with
temperatures moderating to the upper 40s to near 50 by the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 734 PM EDT SUN OCT 31 2021
Conditions at IWD/CMX/SAW will remain high-end MVFR to VFR through
this fcst period. VFR conditions this evening are expected to fall
into high-end MVFR tonight, before lifting back into VFR by late
tomorrow morning. Lake-effect shrasn will remain transient through
this fcst period under WNW winds, impacting all terminals, but due
to transient nature, have left as VCSH. As a cool air mass remains
over the region, expect gusty conditions at all terminals through
the fcst period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 258 PM EDT SUN OCT 31 2021
In the wake of this morning`s cold front, increased instability and
mixing will support nw winds of 20-30kt across Lake Superior tonight
into Monday. Over the e half, expect frequent gale force gusts to
around 35kt into early evening where Gale Warning is in effect.
Winds will then gradually diminish with gusts falling off to blo
20kt by late Tue and remaining under 20kt for Wed. West winds may
increase a bit on Thu as pres gradient tightens slightly btwn high
pres ridging to the s and a low pres trough dropping across Hudson
Bay.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
UPDATE...JAW
SHORT TERM...Voss
LONG TERM...NL
AVIATION...JAW
MARINE...Voss